 /*******************************************************************************
  * Copyright (c) 2000, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.part;

 import java.util.ArrayList ;
 import java.util.HashSet ;
 import java.util.Iterator ;

 import org.eclipse.core.expressions.Expression;
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.jface.action.MenuManager;
 import org.eclipse.jface.viewers.ISelectionProvider;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.ui.IActionBars;
 import org.eclipse.ui.IViewSite;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.IWorkbenchPart;
 import org.eclipse.ui.IWorkbenchWindow;
 import org.eclipse.ui.SubActionBars;
 import org.eclipse.ui.commands.ICommandService;
 import org.eclipse.ui.contexts.IContextService;
 import org.eclipse.ui.handlers.IHandlerService;
 import org.eclipse.ui.internal.PartSite;
 import org.eclipse.ui.internal.PopupMenuExtender;
 import org.eclipse.ui.internal.commands.SlaveCommandService;
 import org.eclipse.ui.internal.contexts.NestableContextService;
 import org.eclipse.ui.internal.expressions.ActivePartExpression;
 import org.eclipse.ui.internal.handlers.NestableHandlerService;
 import org.eclipse.ui.internal.services.INestable;
 import org.eclipse.ui.internal.services.ServiceLocator;
 import org.eclipse.ui.services.IServiceScopes;

 /**
  * This implementation of <code>IPageSite</code> provides a site for a page
  * within a <code>PageBookView</code>. Most methods are forwarded to the
  * view's site.
  */
 public class PageSite implements IPageSite, INestable {

     /**
      * The list of menu extender for each registered menu.
      */
     private ArrayList menuExtenders;

     /**
      * The "parent" view site
      */
     private IViewSite parentSite;

     /**
      * A selection provider set by the page. Value is <code>null</code> until
      * set.
      */
     private ISelectionProvider selectionProvider;

     /**
      * The localized service locator for this page site. This locator is never
      * <code>null</code>.
      */
     private final ServiceLocator serviceLocator;

     /**
      * The action bars for this site
      */
     private SubActionBars subActionBars;

     /**
      * Creates a new sub view site of the given parent view site.
      *
      * @param parentViewSite
      * the parent view site
      */
     public PageSite(IViewSite parentViewSite) {
         Assert.isNotNull(parentViewSite);
         parentSite = parentViewSite;
         subActionBars = new SubActionBars(parentViewSite.getActionBars(), this);

         // Initialize the service locator.
 this.serviceLocator = new ServiceLocator(parentSite);
         initializeDefaultServices();
     }

     /**
      * Initialize the slave services for this site.
      */
     private void initializeDefaultServices() {
         final IWorkbenchPart parentPart = parentSite.getPart();
         final Expression defaultExpression = new ActivePartExpression(
                 parentPart);

         final IHandlerService parentService = (IHandlerService) parentSite
                 .getService(IHandlerService.class);
         final IHandlerService slave = new NestableHandlerService(parentService,
                 defaultExpression);
         serviceLocator.registerService(IHandlerService.class, slave);

         final IContextService contextParent = (IContextService) serviceLocator
                 .getService(IContextService.class);
         final IContextService contextSlave = new NestableContextService(
                 contextParent, defaultExpression);
         serviceLocator.registerService(IContextService.class, contextSlave);
         
         final ICommandService parentCommandService = (ICommandService) serviceLocator
                 .getService(ICommandService.class);
         final ICommandService commandService = new SlaveCommandService(
                 parentCommandService, IServiceScopes.PAGESITE_SCOPE,
                 this);
         serviceLocator.registerService(ICommandService.class, commandService);

     }

     /**
      * Disposes of the menu extender contributions.
      */
     protected void dispose() {
         if (menuExtenders != null) {
             HashSet managers = new HashSet (menuExtenders.size());
             for (int i = 0; i < menuExtenders.size(); i++) {
                 PopupMenuExtender ext = (PopupMenuExtender) menuExtenders.get(i);
                 managers.add(ext.getManager());
                 ext.dispose();
             }
             if (managers.size()>0) {
                 for (Iterator iterator = managers.iterator(); iterator
                         .hasNext();) {
                     MenuManager mgr = (MenuManager) iterator.next();
                     mgr.dispose();
                 }
             }
             menuExtenders = null;
         }
         subActionBars.dispose();
         serviceLocator.dispose();
     }

     /**
      * The PageSite implementation of this <code>IPageSite</code> method
      * returns the <code>SubActionBars</code> for this site.
      *
      * @return the subactionbars for this site
      */
     public IActionBars getActionBars() {
         return subActionBars;
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.core.runtime.IAdaptable#getAdapter(java.lang.Class)
      */
     public Object getAdapter(Class adapter) {
         return Platform.getAdapterManager().getAdapter(this, adapter);
     }

     /*
      * (non-Javadoc) Method declared on IPageSite.
      */
     public IWorkbenchPage getPage() {
         return parentSite.getPage();
     }

     /*
      * (non-Javadoc) Method declared on IPageSite.
      */
     public ISelectionProvider getSelectionProvider() {
         return selectionProvider;
     }

     public final Object getService(final Class key) {
         return serviceLocator.getService(key);
     }

     /*
      * (non-Javadoc) Method declared on IPageSite.
      */
     public Shell getShell() {
         return parentSite.getShell();
     }

     /*
      * (non-Javadoc) Method declared on IPageSite.
      */
     public IWorkbenchWindow getWorkbenchWindow() {
         return parentSite.getWorkbenchWindow();
     }

     public final boolean hasService(final Class key) {
         return serviceLocator.hasService(key);
     }

     /*
      * (non-Javadoc) Method declared on IPageSite.
      */
     public void registerContextMenu(String menuID, MenuManager menuMgr,
             ISelectionProvider selProvider) {
         if (menuExtenders == null) {
             menuExtenders = new ArrayList (1);
         }
         PartSite.registerContextMenu(menuID, menuMgr, selProvider, false,
                 parentSite.getPart(), menuExtenders);
     }

     /*
      * (non-Javadoc) Method declared on IPageSite.
      */
     public void setSelectionProvider(ISelectionProvider provider) {
         selectionProvider = provider;
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.internal.services.INestable#activate()
      *
      * @since 3.2
      */
     public void activate() {
         serviceLocator.activate();
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.internal.services.INestable#deactivate()
      *
      * @since 3.2
      */
     public void deactivate() {
         serviceLocator.deactivate();
     }
 }

